key vs kg, What's the Difference?

Which to use

“key” is an adjective and “kg” is a symbol - they look or sound alike but fill different roles in a sentence.

#18,240
“key” frequency rank: #3,770
“kg” frequency rank: 22010
confusion score

Side-by-Side Comparison

Feature	key	kg
Definition	Dominant, principal.	Symbole du kilogramme, unité de mesure de masse du Système international (SI), valant 10³ grammes.

Letter map: key vs kg

Shared letters muted; letters that set key and kg apart highlighted. Shared run: 1.

3 ch

key

2 ch

Grammar separator: key vs kg

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: key is anadjective and kgasymbol. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 22010, derived from the frequency rank of both members and their visual similarity.

key is recorded at frequency rank #18,240, classified as anadj, pronounced \kiː\. kg is at rank #3,770, tagged as asymbol.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 22010, this pair ranks #360,274 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of key vs kg

Shared letters: k. Private to "key": ey. Private to "kg": g.

"key" · 3 letters · shape CVV · "kg" · 2 letters · shape CC

Frequently Asked Questions

Is swapping "key" for "kg" ever safe?

No - they are not even the same part of speech. "key" is an adjective and "kg" a symbol, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "key" vs "kg" - which ranks higher?

"kg" is the more common of the two: it sits at frequency rank #3,770 in our French list, against #18,240 for "key". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Done with this confusable. These links stay specific to "key" and "kg".

Full dictionary entry for "key" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "kg" - compare definitions side by side with the headword page. Word entry
This pair ranks #360,274 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"key" and "kg" also get mixed up with nearby pairs, the highest-scored neighbour is "key vs ky". Nearby pair

Confusion rank #360,274 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.